motions in which the will has no part, the contractions take place much more in the direction of flexion than in that of extension. 2d. In old people the flexors finally become superior to the extensors; for example, the fingers and toes are almost uniformly bent. 3d. In all the motions, the power is always on the side of flexion. The nerves enter the muscles of the extremities at a very acute angle, because the nervous trunks are in the natural direction of these organs. In the trunk, on the contrary, the nerves going from the spine, the cervical especially, enter their muscles at almost a right angle or one less evidently acute; this circumstance is of no importance. Each branch in the fleshy fibres, is at first divided and then sub-divided in their interstices, and afterwards lost in their texture. Does each fibre receive a small nervous filament? We should be led to believe so from this observation, that the principal branch being irritated, all the fibres are put into action, no one remains inert. But on the other hand, if we irritate one of them, all move also, which is certainly a sympathetic phenomenon or one arising from the communication of the cells. Are the nerves deprived of their cellular coverings, and do they become pulpy when they enter the muscles? Dissection has shewn me nothing like it. ARTICLE THIRD. PROPERTIES OF THE MUSCULAR SYSTEM OF ANIMAL LIFE. There are but few systems in the economy in which the vital properties and those of texture are found in so great and evident a degree as in this. It is from the muscles that examples must be selected to give a precise and accurate idea of these properties. The physical properties on the contrary are slightly marked in them; a remarkable softness characterizes them; there is no elastic power in their texture; there is but very little resistance from this texture after death; it is from vitality that it derives the power that characterizes it in its functions. I. _Properties of Texture. Extensibility._